Apparatus for conditioning material



APPARATUS FOR CONDITIONING MATERIAL Filed Feb. 28. 1944 4free/vir Patented June 4, 1946 Edward Joseph Cogovan, Albany, N. Y., assignor to F. C. Huyck & Sons, Rensselaer, N. Y., a corporation of New York Application February 28, 1944, Serial No. 524,324

(Cl. 'i3-73) 3 Claims. 1

My invention relates to a novel apparatus for u conditioning materials of the type which exhibit regain characteristics whereby the moisture content and the bone-dry weight thereof may be determined. It relates particularly, but not exclusively, to an apparatus for determining the moisture content and bone-dry weight of brous materials such as Wool, cotton, rayon, silk7 and the like.

Many materials such as wool, for example, are hygroscopic. That is, they absorb and retain water vapor from the surrounding air. For this reason the weight of a given quantity of material which, of course, is constant when the mate-4 rial is in bone-dry condition, varies according to the quantity of moisture therein, and this, in turn, depends upon the temperature and relative humidity of the atmosphere to which the material has been exposed for a period of time sufficiently long for it to attain a conditioned or equilibrium weight.

The customary method of procedure in determining moisture content and bone-dry weight of a given sample of wool is first, to weigh it and then to condition it in a controlled atmosphere. That is, until it has acquired a weight which re- .mains constant so long as the temperature and the relative humidity of the surrounding atmosphere remain constant. This requires that the sample remain for twenty-four hours or more, in an atmosphere which is maintained at constant temperature and constant relative humidity. When moisture equilibrium has been attained the conditioned sample is again weighed to determine the total weight of the bone-dry material itself plus the moisture therein, and, since the temperature and relative humidity of the atmosphere are known, the percentage weight of moisture in the conditioned sample may be readily determined with the help of a regain chart for that particular material. From the data thus obtained the percentage of moisture in the original sample may be calculated.

Because, by the present methods, it takes hours to bring a, sample of wool or other iibrous material to a condition of moisture equilibrium in order to determine its moisture content, the principal object of my invention is to provide a simple apparatus whereby an accelerated conditioning of the material may be effected.

In general, it may be said that I effect an accelerated conditioning 'of a sample of the material by creating a flow through said sample of comparatively large volumes of air, the temperature and relative humidity of which are known.

until the sample is brought to a condition of moisture equilibrium with said air. I accomplish this result by the apparatus hereinafter described and illustrated in the accompanying drawing in which- Fig. 1 is a top plan view of the apparatus with portions broken away;

Fig. 2 is a side elevation thereof;

Fig. 3 is a right hand end view of the apparatus as illustrated in Figs. 1 and 2.

Referring to the drawing- I is a base to which is secured the electric motor 2 having its axis horizontal and having a supporting standard 3 .which is secured to the base by means ofthe screws 4. 5 is an aspirator housing having a rotor (not shown) therein preferably of the Sirocco type which is driven at high speed by the motor 2. The movement o1" the rotor induces a ow of air into the aspirator housing through the side thereof opposite the motor and discharges the air through the exhaust pipe 6; the air iiowing in the direction of the arrows in Figs. 1 and 3. Secured to the inlet side of the housing by means of the screws 'I is a short tube or duct 8 through which the air is drawn into the housing. The tube 8, at the open end, is preferably provided with a frusto-conical enlargement 9, and a screen Ill, which may have approximately fifty meshes to the linear inch, is secured within the open end of the frustum. Cemented or otherwise secured about the edge of the open base of lthe cone is an annular gasket II of soft rubber. A cup-like receptacle I2, in which the material I3 to be conditioned is placed, is supported on lbracket I4 with its rim held in close engagement with the gasket I I by means of the spring I5 which presses against the bottom of the receptacle. The screen I6 in the bottom of receptacle I2 is preferably somewhat finer than the screen I0 and may, for example, have two hundred meshes to the linear inch. It is quite important to prevent dust and other particles present in the circumambient air from being drawninto the specimen of material being conditioned because they would increase the weight thereof and, depending on the quantity of such foreign matter drawnv into the specimen, might materially affect the accuracy of the bone dry weight determinedftherefrom. In order to remove the receptacle I2 it is necessary only to pull the end Il of the Vspring outwardly and slide the receptacle laterally oi the support I4.

`Secured to the side of the tube 8 is a thermometer I8 and a, hygrometer I9 which are. disposed to indicate, respectively, the temperature and the relative humidity of the air passing through tube 8.

In operation, and assuming that it is desired to ascertain the moisture content and the bonedry weight of a lot of wool, a fair sample of the wool is taken and one ounce thereof is carefully weighed out and packed in the receptacle I2, as shown at I3. The motor is then started by electrically connecting the lead wires 20 to any vaccessible source of power. The aspirator, driven by the motor 2, reduces the air pressure in the tube 8, and thus a flow of the surrounding air under atmospheric pressure is created through the screen I6, the material I3, screen I0, tube 8, and the aspirator housing, and is discharged through the pipe 6. Depending upon the temperature and moisture differentials between the material being conditioned and the surrounding air, which of course affect the condition of the air passing through the tube 8, movements of either one or both of the indicators I8 and I9 will be produced and will continue until these differentials have been reduced to zero. When the readings of these indicators have remained constant for a few minutes the air flowing through the tube 8 is no longer being affected by its passage tlfnough the material I3 andthe material has reached a conditioned or equilibrium weight in an atmosphere of the temperature and relative humidity indicated by the Vthermometer I8 and the hygrometer I9. The atmosphere, of course, is the surrounding air.

When the conditioning of the material has been effected, the aspirator is shut oi and the material removed from thereceptacle I2 and carefully reweighed. The regain in percent under the conditions of temperature and relative humidity indcated by the thermometer and hygrometer are noted from a standard regain chart and from these data the bone-dry weight of the sample and the original regain of the same in its original condition may be calculated as follows:

Conditioned weight Bone'dry WelghtzRegain in percent+ 100 From the foregoing it will be apparent that by my apparatus any material which exhibits regain characteristics may be very quickly conditioned so that its equilibrium weight can be ascertained and its bone-dry weight and original regain calculated from the equilibrium weight with the assistance of authentic regain charts or tables prepared for the particular material.

Materials may be conditioned from any state to a state in which they are in equilibrium with the surrounding atmosphere in a matter kof ten to fifteen minutes as compared with the twentyfour or more hours required by the present methods. Thus, wool, cotton, rayon, silk and other fibrous materials as such, or in the form of textiles, and cellulose products, such as paper when finely cut so as to provide a porous mass, may be very quickly conditioned. The apparatus may be used under any atmospheric conditions of temperature and humidity for which the regain characteristics of the material being tested have been determined. Such characteristics maybe determined by the standard methods prescribed bythe American Society for Testing Materials.

Except for a change in its moisturecontentand a negligible loss in highly volatile impurities, if any are present, the treatment does not in any Way affect the sample and, since the air is drawn through the sample prior to reaching the aspirator or coming in Contact with any portions of the aspirator or the motor which may become heated during operation, the results are very accurate.

As pointed out above, a large volume of air at known and substantially constant temperature and relative humidity must-be forced through the sample if accurate determinations of the bone dry weight and the original regain of the sample in its original condition are to be made. It is quite impossible to attain a true moisture equilibrium between a hygroscopic material and an atmosphere which is constantly recirculated through the sample in a closed system because the work done on such a limited volume of air by the circulating fan always results in a progressive rise in the temperature of the air. Furthermore, it is well known that an electric motor, which is at the temperature of the circumambient air when rst started, heats up quite rapidly and to a substantial degree when in operation,fand that a rotor driven thereby and the rotor housing and other parts intimately associated with the motor also undergo a rise in temperature by heat conduction therefrom. Even where the `blower or aspirator is not directly driven by the motor (as in the case of a belt drive) and is not so intimately associated with the motor as to.be affected-by heat conduction therefrom, it may, nevertheless, undergo an appreciable increase in temperature due to belt friction, friction in the bearings, air

friction, and other causes, so that the temperature of the air passing therethrough may Vbe affected. Thus, where the air passes rst through the blower and then through the material being conditioned there is always the possibility that the results may be affected to a greater or lesser degree depending on the design of the particular apparatus and other factors. f

Hence, where only approximate determination of bone dry weight are required, air from a substantially unlimited source may be forced through the test specimen under pressure developed by the blower, but, where accurate determinations are required, the air must be aspirated through the test specimen. In any case, large volumes of air are required, and it is quite impossible to make even a closely approximate determination of bone dry weight by recirculating a limited Volumeiof air through a closed system.

While I have described my invention in'its preferred form it is to be understood that the words which I have used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from thegtrue scope vand spirit of the invention in its broader aspects.

What I claim is:

l. A compact, unitary device for quickly conditioning materialv having regain characteristics, said device comprisinga blower including `a housing provided with means forming an air intake passage for said blower communicating with fthe circumambient air, an electric motor directly connected to said blower for driving the same,`fa screen through which the intake'n air passes before reaching said blower, and* means in said passage intermediate said screen and said blower for indicatingtthe temperature and relative humidity of the air'passing through said screen; whereby, a specimen'of said material of accurately .predetermined weight may vbepositi'o'ned against said screen Yand quickly brought into 'a condition of moisture equilibrium with the circumambient air.

2. A device for conditioning material comprising means forming an air passage of substantial cross sectional area open at each end to the circumambient air; means for forcing a :dow of the circumambient air in substantial volume at substantial velocity through said passage, means for retaining a small specimen mass of said material of predetermined weight in such substantially fixed relation to said passage that the air flowing through said passage will pass through said specimen, means for intercepting dust particles and the like in said air before it passes through said specimen, and means disposed in the air stream for indicating when the temperature and relative humidity of the air passing through said specimen becomes constant.

3. A device for conditioning material comprising means, including an aspirator housing, forming an air duct of substantial cross sectional area open at each end to the circumarnbient air, a

rotor in said housing, means for driving said rotor, whereby to create a free ow of the circumambient air into one end of said duct and discharge it from the other end thereof, means for retaining a small specimen of said material of accurately predetermined weight exposed to the current of air owing into said duct before said air passes through said aspirator housing, means in said duct for intercepting dust particles and the like in said air before it reaches said specimen, and means disposed in the air stream for indicating when the temperature and relative humidity of the air passing through said specimen becomes constant; whereby the temperature of the air to which said specimen is exposed Will be unaffected by contact with said aspirator or by the action of said aspirator thereon, and said specimen may be quickly brought into substantially true moisture equilibrium with the circumambient air.

EDWARD JOSEPH COGOVAN. 

